Cataract Surgery Complications and Side Effects

Table of Contents
View All
Table of Contents

Cataract surgery is a very common type of eye surgery. A cataract is when your eye’s lens, the thin covering at the front of your eyeball, is clouded over. Less light can get through, and it becomes harder and harder to see as the cataract gets worse. 

In cataract surgery, your damaged lens is removed. Then a man-made version, called an intraocular lens, is implanted. This procedure restores eyesight in 90% of cases.

About 3.6 million people each year have cataract surgery in the United States. The tools and procedures have become very advanced, and complications are fairly rare.

Still, there are risks related to any surgery. Problems after surgery are more likely if you have other eye problems or medical conditions.

60-year-old man gets prepped for cataract surgery
Will & Deni McIntyre / Getty Images 

This article will explain the type of side effects that are common after cataract surgery as well as serious complications that could occur and how they're treated.

Normal Side Effects

The most common side effects of cataract surgery are minor. These issues usually go away within a short period of time without any additional treatment.


It’s natural for the eye that’s been operated on to feel itchy while you heal. Your physician may be able to prescribe eye drops that can relieve the itchiness.

Call your doctor if the feeling goes away but starts again days later or anytime it feels unbearable. In some cases, itchiness could be a sign of infection.

Blurry Vision 

You should expect your vision to be a bit blurry at first, but it should quickly get better. Don’t drive until your vision is totally clear.


Some inflammation, which includes swelling and redness, is normal after cataract surgery. Your doctor should be able to ease the inflammation with drops. Inflammation that doesn’t go away and gets worse can be a sign of an infection, which your doctor needs to treat as soon as possible.


Floaters are spots that come in and out of your line of vision. They usually look like floating dots or squiggly threads. What you’re seeing is actually clumps of the gel-like substance that makes up the inside of the eyeball.

Floaters can form if the gel separates from the retina during cataract surgery. This is called posterior vitreous detachment. These usually fade over time and don’t cause pain.

There’s no treatment for floaters in these cases. However, talk to your doctor if you start to notice more floaters and you have eye pain or other vision problems.

Light Sensitivity

After surgery, it’s normal to feel like everyday light is a little too bright. It may feel uncomfortable for a few days. Some people even need to wear sunglasses until the sensitivity is completely gone. If the sensitivity doesn’t go away, it may be a sign that you have an infection and need to get treatment.

Droopy Eyelid

After surgery, the eyelid may hang down slightly. This called ptosis or droopy eyelid. It may be caused by the instrument used to hold back the eyelid during cataract surgery or the anesthesia used, but doctors say it could be due to several things. 

Usually, the droopiness is temporary. If it doesn’t go away on its own, you might need surgery to correct it.

Most Common Complications

More than 99% of people who receive cataract surgery have no complications. Though it's a very safe procedure, complications do sometimes happen.

These problems include damage to the eye structure or contamination of the eye. The effects can usually be reversed, allowing you to enjoy clear vision.

Posterior Capsular Opacification (PCO)

When complications do occur, they’re often related to posterior capsular opacification. PCO is sometimes called “secondary cataracts” because it causes clouded vision similar to cataracts.

When the lens is implanted in your eye during cataract surgery, it rests on a thin film called a capsule. Cells sometimes build up on this capsule behind the new lens. The capsule thickens and blocks your vision.

There’s no way to tell who might get PCO after cataract surgery, but there are certain types of lenses that reduce the odds of PCO.

Doctors can easily treat PCO. First, they numb the eye with eye drops. Then, a laser removes the layer of cells on the capsule.


An infection can develop inside the eye, known as endophthalmitis. This type of infection is usually caused by bacteria getting into the eye during surgery. The most common bacterial infection is due to Staphylococcus epidermidis, which is found naturally on the eyelids and skin.

If it enters the eye itself during or after surgery, it can cause severe pain, redness, and blindness.

Once diagnosed with an infection, you need to start antibiotics immediately. If the infection has already spread, you may also need to have surgery to remove damaged tissue.

Tell your doctor immediately if you have signs of infection such as:

  • Redness
  • Swelling
  • Green, yellow, or milky discharge

Wound Leak

Any eye surgery carries the risk of a blood vessel in the retina opening. This makes fluid collect in the eye, and that fluid will leak out. This is fairly common, and as long as it’s noticed early, it can be treated easily. Waiting too long can lead to an infection.

For nine out of 10 people with cataracts, surgery totally restores their eyesight. The most common risks are easily treatable. It’s important, though, to follow post-op treatment plans such as using eye drops and seeing your doctor for follow up visits so you can catch an infection or PCO early.

Rare Complications

Some of the complications discussed below can sound very serious and scary. Keep in mind that they occur very rarely. Doctors are very experienced with dealing with these problems, so long-term complications are unlikely.

Double Vision

Double vision, known as diplopia, is when you see one object as two. In rare instances, it can develop after cataract surgery. There are a number of reasons why it might occur.

Once your doctor understands what caused the double vision, there are several options to correct it:

  • Eye exercises 
  • Special eye glasses 
  • Medication injected into the eye
  • Surgery

Retinal Detachment

The retina is a layer of tissue that covers the back of the eye. During surgery, this can become separated from the tissue under it. That can significantly hurt your vision. Your doctor will need to reattach the retina and repair any tears.

Unfortunately, even after the retina is fixed, you may have long-term problems related to the retinal damage. 

Bleeding in the Eye

Bleeding in the eye is known as suprachoroidal hemorrhage. This is when blood builds up between the thin layers of the eye during cataract surgery. 

Thanks to modern surgical methods, this doesn’t happen often. When it does, it can often be treated with medication. Sometimes it goes away on its own.

Swelling of the Macula

The macula is in the center of the retina. It is the area of your vision in which you see images most sharply and clearly. Fluid can build up in the macula after cataract surgery. This causes swelling known as edema. The fluid buildup may start a few weeks after surgery.

Eye drops can reduce the swelling, so the condition usually doesn’t last too long.

Only about 1% to 3% of people who have cataract surgery develop macular edema. Still, it’s the most common cause of vision loss after cataract surgery. This swelling happens much more often than retinal detachment or endophthalmitis.

Increased Intraocular Pressure (IOP)

Inside the eye is fluid known as the aqueous humor. The fluid sometimes collects in the eye and causes pressure to build up.

Increased IOP occurs in up to about 10% of cataract surgeries. In most cases, the pressure will return to normal within a few hours.

If your IOP doesn’t get better, you could end up with severe complications, including:

  • Swelling of the cornea
  • Pain
  • Damage to the optic nerve
  • Damage to veins in the eye

You’re more likely to have a problem if you already have optic nerve damage from glaucoma or stroke.

Toxic Anterior Segment Syndrome (TASS)

TASS affects the back of the eye. It’s usually caused by contaminants getting into the eye from surgical equipment. This leads to edema, inflammation, and other symptoms.

If you’re exposed to the contaminated material during surgery, you might show signs of TASS within 24 hours.

Applying steroid ointment or cream to the eyes or taking oral steroids can cure TSS. However, the damage caused by the inflammation can still result in permanent damage to your eyesight.

Retained Lens Fragments

Even the most skilled eye surgeons sometimes have problems completely removing cataracts. A piece of the original lens with cataracts may remain in the eye after surgery. This can lead to inflammation, increased pressure in the eye, swelling of the retina and cornea, and possible vision loss.

Doctors will need to operate again if a fragment is accidentally left behind.

Iris Prolapse

A prolapse is when something bulges or falls out. In the case of iris prolapse, the colored part of your eye (the iris) comes out of its fixed position. This can happen as a surgeon is operating on the eye. Iris prolapse is very rare. Today’s surgical instruments are more precise, and they prevent the iris from coming out.

Intraocular Lens Dislocation (IOL)

Occasionally, the lens implanted during cataract surgery moves out of place. This dislocation of the lens happens if the capsule surrounding the lens bursts.

IOL can occur within days of the surgery or years later. Being hit in the eye increases the risk of your lens being dislocated. 

Sometimes, the lens moves, but there’s no change to your vision or the health of the eye. In these instances, you don’t need to do anything. If your vision is affected, you’ll need surgery again to fix the lens.

Medical advances have made cataract surgery even safer than it was a decade ago. Surgery can be risky, though. Possible complications could be due to:

  • A doctor error that results in a piece of the cataract being left behind
  • Bacteria or other foreign substances contaminating the eye
  • Fluid or blood building up during surgery

Doctors can usually successfully treat problems that come up. There is, though, a risk of permanent loss of eyesight or discomfort after the operation.

Risk Factors

Complications from cataract surgery are sometimes related to the unavoidable risks of surgery. But certain factors increase the likelihood of problems during or after your operation:

  • Macular degeneration 
  • Diabetic retinopathy, damage to the eye caused by diabetes
  • Corneal opacity, when the cornea is scarred from injuries, scratches, or swelling of the eye
  • Age (older adults are more likely to have problems)
  • Being a woman
  • Previous eye surgery
  • Having already had a detached retina
  • Taking alpha-blocker medication for blood pressure
  • Having other serious illnesses such as hypertension, diabetes, cancer, or thyroid disease, all of which affect how well you heal from surgery

If you have diabetes and your blood glucose levels are not under control, it can be more difficult to heal after surgery.


Cataract surgery is a very effective way to cure a common eye problem. In the vast majority of cases, it helps to save a person’s eyesight. However, you should be prepared for some temporary vision problems like blurriness. These usually go away on their own as you heal.

In rare instances, there are complications. If you have other health issues, additional eye problems, or are over 80, you’re more likely to have complications during or after cataract surgery.

Following up with your doctor and taking care of any problems that come up will help you heal well and enjoy better vision.

A Word from Verywell

Many people avoid having cataracts removed because they are afraid of surgery. It’s understandable and very normal to worry about any operation. Thankfully, though, cataract surgery had become a very routine procedure. Doctors perform the operation so often, they should be prepared for any complications that arise.

Considering the fact that your eyesight will definitely get worse if cataracts are not treated, it’s worthwhile to consider the pros of surgery.

Talking with people who have had the operation can ease some worries. Don’t be afraid to ask your doctor many questions. Getting answers can help you to relax and heal better after the operation.

18 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Eye Institute. Cataract surgery.

  2. Grzybowski A. Recent developments in cataract surgery. Ann Transl Med. 2020;8(22):1540-1540. doi:10.21037/atm-2020-rcs-16

  3. Taravati P, Lam DL, Leveque T, Van Gelder RN. Postcataract surgical inflammation. Curr Opin Ophthalmol. 2012;23(1):12-18. doi:10.1097/icu.0b013e32834cd60e

  4. Cleveland Clinic. Posterior vitreous detachment.

  5. Koh V, Tatsios J, Chew PK, Amrith S. Comparison of incidence of ptosis after combined phacotrabeculectomy with mitomycin C and phacoemulsification. Indian J Ophthalmol. 2015;63(12):895. doi:10.4103/0301-4738.176032

  6. Aaronson A, Viljanen A, Kanclerz P, Grzybowski A, Tuuminen R. Cataract complications study: an analysis of adverse effects among 14,520 eyes in relation to surgical experience. Ann Transl Med. 2020;8(22):1541. doi:10.21037/atm-20-845

  7. University of Michigan Health. Nd:YAG laser posterior capsulotomy after cataract surgery.

  8. American Academy of Ophthalmology. Cataract surgery complications.

  9. Scheer L, Marcus-Freeman S. Using optical coherence tomography in the management of postoperative wound leaks after cataract surgery. Fed Pract. 2019;36(8):356-364.

  10. Gawęcki M, Grzybowski A. Diplopia as the complication of cataract surgery. J Ophthalmol. 2016;2016:1-6. doi:10.1155/2016/2728712

  11. Petousis V, Sallam AA, Haynes RJ, et al. Risk factors for retinal detachment following cataract surgery: the impact of posterior capsular rupture. Br J Ophthalmol. 2016;100(11):1461-1465. doi:10.1136/bjophthalmol-2015-307729

  12. American Academy of Ophthalmology. Management of suprachoroidal hemorrhage.

  13. National Eye Institute. Macular edema.

  14. Grzybowski A, Kanclerz P. Early postoperative intraocular pressure elevation following cataract surgery. Curr Opin Ophthalmol. 2019;30(1):56-62. doi:10.1097/ICU.0000000000000545

  15. Park CY, Lee JK, Chuck RS. Toxic anterior segment syndrome—an updated review. BMC Ophthalmol. 2018;18(1):276. doi:10.1186/s12886-018-0939-3

  16. American Society for Retina Specialists. Retained lens fragments.

  17. American Society of Retina Specialists. Intraocular lens dislocation.

  18. Peterson SR, Silva PA, Murtha TJ, Sun JK. Cataract surgery in patients with diabetes: management strategies. Semin Ophthalmol. 2018;33(1):75-82. doi:10.1080/08820538.2017.1353817

By Jennifer Whitlock, RN, MSN, FN
Jennifer Whitlock, RN, MSN, FNP-C, is a board-certified family nurse practitioner. She has experience in primary care and hospital medicine.